Exchange-traded funds (ETFs) can be a valuable component for any investor's portfolio, from the most sophisticated institutional money managers to a novice investor who is just getting started. Some investors use ETFs as the sole focus of their portfolios, and are able to build a well-diversified portfolio with just a few ETFs. Others use ETFs to complement their existing portfolios, and rely on ETFs to implement sophisticated investment strategies. But, as with any other investment vehicle, in order to truly benefit from ETFs, investors have to understand and use them appropriately.

From an investor's perspective, an investment in an index mutual fund and an ETF that tracks the same index would be equivalent investments. For example, the performance of the SPDR S&P 500 ETF and a low-cost index fund based on the S&P 500 would both be very close to the to the S&P 500 index in terms of performance.

Although index mutual funds are available to cover most of the major indexes, ETFs cover a broader range of indexes, providing more investing options to the ETF investor than the index mutual fund investor. (For more insight, read ETFs Vs. Index Funds: Quantifying The Differences.)

This tutorial provides a basic understanding of what an ETF is and how it might be used by an investor.